TY - JOUR
T1 - DdrB stimulates single-stranded DNA annealing and facilitates RecA-independent DNA repair in Deinococcus radiodurans
AU - Xu, Guangzhi
AU - Lu, Huiming
AU - Wang, Liangyan
AU - Chen, Huan
AU - Xu, Zhenjian
AU - Hu, Yihuai
AU - Tian, Bing
AU - Hua, Yuejin
PY - 2010/7/1
Y1 - 2010/7/1
N2 - The bacterium Deinococcus radiodurans can survive extremely high exposure to ionizing radiation. The repair mechanisms involved in this extraordinary ability are still being investigated. ddrB is one gene that is highly up-regulated after irradiation, and it has been proposed to be involved in RecA-independent repair in D. radiodurans. Here we cloned, expressed and characterized ddrB in order to define its roles in the radioresistance of D. radiodurans. DdrB preferentially binds to single-stranded DNA. Moreover, it interacts directly with single-stranded binding protein of D. radiodurans DrSSB, and stimulates single-stranded DNA annealing even in the presence of DrSSB. The post-irradiation DNA repair kinetics of a ddrB/recA double mutant were compared to ddrB and recA single mutants by pulsed-field gel electrophoresis (PFGE). DNA fragment rejoining in the ddrB/recA double mutant is severely compromised, suggesting that DdrB-mediated single-stranded annealing plays a critical role in the RecA-independent DNA repair of D. radiodurans.
AB - The bacterium Deinococcus radiodurans can survive extremely high exposure to ionizing radiation. The repair mechanisms involved in this extraordinary ability are still being investigated. ddrB is one gene that is highly up-regulated after irradiation, and it has been proposed to be involved in RecA-independent repair in D. radiodurans. Here we cloned, expressed and characterized ddrB in order to define its roles in the radioresistance of D. radiodurans. DdrB preferentially binds to single-stranded DNA. Moreover, it interacts directly with single-stranded binding protein of D. radiodurans DrSSB, and stimulates single-stranded DNA annealing even in the presence of DrSSB. The post-irradiation DNA repair kinetics of a ddrB/recA double mutant were compared to ddrB and recA single mutants by pulsed-field gel electrophoresis (PFGE). DNA fragment rejoining in the ddrB/recA double mutant is severely compromised, suggesting that DdrB-mediated single-stranded annealing plays a critical role in the RecA-independent DNA repair of D. radiodurans.
KW - DdrB
KW - Deinococcus radiodurans
KW - RecA-independent DNA repair
KW - SSA
UR - http://www.scopus.com/inward/record.url?scp=77953323321&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=77953323321&partnerID=8YFLogxK
U2 - 10.1016/j.dnarep.2010.04.006
DO - 10.1016/j.dnarep.2010.04.006
M3 - Article
C2 - 20451472
AN - SCOPUS:77953323321
SN - 1568-7864
VL - 9
SP - 805
EP - 812
JO - DNA repair
JF - DNA repair
IS - 7
ER -